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Volume 35 (1996)
- Issue 5 Pages 349-
- Issue 4 Pages 281-
- Issue 3 Pages 153-
- Issue 2 Pages 75-
- Issue 1 Pages 1-
Volume 35, Issue 2
Displaying 1-7 of 7 articles from this issue
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Hirofumi Yamamoto, Tomio Nakagawa, Fusao Arai1996 Volume 35 Issue 2 Pages 75-85
Published: May 31, 1996
Released on J-STAGE: August 21, 2009
JOURNAL FREE ACCESSMarine terraces along the Echizen Coast on the Sea of Japan side of central Japan have been investigated with special reference to their tectonic uplift during the late Pleistocene period. A large part of the Echizen Coast consists of a flight of marine terraces which are classified into three groups called the Holocene terrace, the middle terrace group, and the higher terrace group. The middle terrace group is further subdivided into three terraces, named M1, M2, and M3 in descending order of elevation. M1 and M2 have wide surfaces, and M3 has narrow surfaces in places between the M2 and the Holocene terraces.
Some tephras obtained from the terrace deposits and from the topsoil covering them are identified with the Sambe Kisuki tephra, the Kikai-Tozurahara tephra, the Aso-4 tephra, the Daisen Kurayoshi tephra, the Aira-Tn tephra, and the Kikai-Akahoya tephra. These tephras and topographic features show that M1 can be correlated with the Shimosueyoshi terrace, M2 with the Obaradai terrace, and M3 probably with the Misaki terrace in the southern Kanto area.
The average uplift rates along the Echizen Coast are calculated, based on the height of the former shorelines preserved on these terrace surfaces, the age of these formed terraces, and the paleo-sealevel height, to be 0.2 to 0.5 meter per 1, 000 years in the northern area, 0.6 to 0.9 meter per 1, 000 years in most other areas, and the highest rate of 1.0 to 1.2 meters per 1, 000 years at the northeast end of the Cape of Echizen. These high rate of tectonic uplift of the Echizen Coast seems to be related to the activity of the Kaburagi Fault along the coast.View full abstractDownload PDF (1644K) -
Shuichiro Yoshinaga1996 Volume 35 Issue 2 Pages 87-98
Published: May 31, 1996
Released on J-STAGE: August 21, 2009
JOURNAL FREE ACCESSThe presence of silt-sized quartz in andesitic or basaltic wethered volcanic ash soils has indicated the additions of non-volcanogenic material through soil accumulation. The oxygen isotope composition of the quartz revealed that it originated from tropospheric dust transported from inland China by the northwest winter monsoon. Thus, the fluctuation of the quartz accumulation rate indicates the fluctuation of northwest winter monsoon intensity. Series of the quartz accumulation rate since the Last Interglacial age, obtained at the Saotome section in the north-Kanto Plain, demonstrate the fluctuation simultaneous with the standard marine oxygen isotope variation. The quartz accumulation rate increases in oxygen isotope stages 2, 4 and 5b, indicating cold climate episodes, and decreases in stages 1, 3 and 5a, indicating warm climate episodes. This fluctuation suggests a strengthening of the northwest winter monsoon during cold stages and weakening during warm stages, a finding that agrees well with variations of quartz accumulation rate in the Tokachi Plain and with variations of the grain size distribution and the accumulation rate of loess-paleosol sequence in the Chinese Loess Plateau.View full abstractDownload PDF (1638K) -
Hiroshi Sato, Yoshihiro Tanimura, Yusuke Yokoyama1996 Volume 35 Issue 2 Pages 99-107
Published: May 31, 1996
Released on J-STAGE: August 21, 2009
JOURNAL FREE ACCESSA diatom form, tentatively named Melosira sp. 1, with strongly silicified hemispherical valves or sub-spherical frustules, occurs in the sedimentary sequences recording Holocene sea-level changes in Japan. It reaches maximum abundance in the uppermost part of marine facies formed as a result of Holocene transgression, and disappears in overlying freshwater sediments at several sites along the coastal areas in Japan. Its distinctive morphology, corrosion resistant thick valves, common occurrence with abundance peaks near the upper limit of marine facies described in this paper and occurrence in the present-day tidal flat reported by Kosugi (1986, 1988), should make this diatom form one of the useful indicators for identifying marine limit. The abundance peaks of the form indicating former sea-level stand during the Holocene would be helpful to reconstruct local histories of Holocene sea-level changes in Japan.View full abstractDownload PDF (1760K) -
Kunihiko Endo, Hitoshi Fukusawa1996 Volume 35 Issue 2 Pages 111-112
Published: May 31, 1996
Released on J-STAGE: August 21, 2009
JOURNAL FREE ACCESSLake sediments represent high-resolution records of important informatin on the local, regional and global environmental changes. Studies of lake sediments are important for improving many models of global changes and for making realistic predictions on the future environmental system.View full abstractDownload PDF (307K) -
Coastal Lagoon Sediments as Carbon SinkYoshikazu Sampei, Eiji Matsumoto, Takao Tokuoka, Daiei Inoue1996 Volume 35 Issue 2 Pages 113-124
Published: May 31, 1996
Released on J-STAGE: August 21, 2009
JOURNAL FREE ACCESSThe organic carbon (Corg.) accumulation rate and its relation to climate change during the last 8, 000 years as recorded in the sediment core from the semi-closed coastal lagoon Lake Nakaumi were reconstructed. High-resolution downcore profiles of 14C by fifteen shells enabled us to conclude that the Corg. accumulation rate in a warming climate (7, 000-7, 500cal yrs BP; Calendar age) was about two times higher than that in a cooling climate (2, 500-3, 000cal yrs BP). The coastal lagoon could provide a small negative feedback on global warming and an effective small sink (ca. 0.01 GtC yr-1) for atmospheric CO2.View full abstractDownload PDF (1370K) -
Masayuki Hyodo, Sumiyo Minemoto1996 Volume 35 Issue 2 Pages 125-133
Published: May 31, 1996
Released on J-STAGE: August 21, 2009
JOURNAL FREE ACCESSPaleomagnetic studies of lake bottom sediments in Japan have been reviewed to establish a method of magnetostratigraphic dating using geomagnetic secular variations and excursions. For the last 11.6ka, declination and inclination changes can be used as magnetostratigraphic time markers for dating. For the last 60ka, the inclination record from the top 60m of the 200m-core from Lake Biwa may be used for dating with magnetostratigraphic correlation. Tephrochronological data recently published revise the ages of the geomagnetic excursions in the Lake Biwa 200m-core. The excursion at 54m, formally known as the Blake event, is a new one from about 56ka. The Biwa I excursion at 83m, newly dated as 116ka, should correspond to the Blake event. The Biwa II excursion at 131m is newly dated as 188ka. We propose that the three thin zones of negative inclination at 25.8m, 33.8m, and 35.2m are excursions, having occurred at 24ka, 33ka, and 34ka. The six geomagnetic excursions from the Lake Biwa 200m-core are useful for magnetostratigraphic dating for the last 300ka around Japan.View full abstractDownload PDF (1111K) -
1996 Volume 35 Issue 2 Pages 138
Published: 1996
Released on J-STAGE: August 21, 2009
JOURNAL FREE ACCESSDownload PDF (48K)
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